Generally, in a multi-needle embroidery sewing machine, needle threads of different colors are passed through a plurality of corresponding needles provided on a sewing machine head. In such multi-needle embroidery sewing machine, a color change mechanism moves the sewing machine head to locate one of the needles in a sewing position, and a multi-color embroidery pattern is formed on a work cloth held on an embroidery frame with the selected needle thread passing through the needle in the sewing position. In such kind of embroidery sewing machine, there has conventionally been known a needle thread feeding device in which the quantity of use of the selected needle thread is predetermined by considering the quantity of movement of the embroidery frame as well as the materials of the needle thread and the cloth, and the predetermined quantity of the selected needle thread is fed out from a needle thread supply source to the needle in the sewing position.
For example, the needle thread feeding device described in Patent Literature 1 (Japanese Patent Application Publication No. JP-A-59-59961) is equipped with the same number of feed rollers as the number of needles on the sewing machine head. Each of the feed rollers is connected to a motor through a switching mechanism, and rotational speed of the motor is controlled based on a predetermined quantity of use of a thread. The needle thread feeding device is then structured so as to wind a plurality of needle threads on the respectively different feed rollers, to selectively transmit power of the motor to each of the feed rollers through gears of the switching mechanism, and to feed out the predetermined quantity of the selected needle thread to the needle in a sewing position.